Thermal desorption spectrometer for measuring ppm concentrations of trapped hydrogen. (12th April 2018)

• Record Type: Journal Article
• Authors: Tapia-Bastidas, C.V.; Atrens, A.; Gray, E. MacA.
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 15(2018)
• Page Start: 7600
• Page End: 7617
• Publication Date: 2018-04-12
• Subjects: Thermal desorption spectroscopy -- Hydrogen trapping -- Steel -- Water adsorption; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.02.161
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: This paper describes an ultra-high-vacuum thermal desorption spectrometer, designed to study hydrogen in steels at ∼1 wt ppm (∼50 atomic ppm) concentration. The high sensitivity achieved also facilitates the analysis of surface phenomena. The instrument was evaluated with model materials and provided good measurements of diffusible hydrogen. A hydrogen peak at ∼350 °C was identified for steels exposed to water during hydrogen charging, and attributed to water molecules adsorbed on the sample surface for samples exposed to the laboratory atmosphere for times as short as 1 min. Recommendations are made for precautions to be taken when handling the samples. Highlights: Ultra-high vacuum TDS with baseline capability to measure a spectrum for a sample containing just 20 ng of hydrogen. Integrated calibration facility. Utility for both ppm-level embrittlement studies and trapped H in storage materials. TDS theory fully expounded and common implicit assumptions exposed in relation to both calibration and measurement. Includes a study of the problem of spurious hydrogen from decomposition on the sample of adventitious water.